Question

Please answer all the questions. No explanation needed.

6. (pr) If a met-thr-Str. Hfr strain is mated with an F- of genotype lew-thi-Str prototrophic recombinants may be detected by plating the mixture on: A. Leucine and methionine + Streptomycin B. Threonine and thiamine + Streptomycin C. Leucine and thiamine and Streptomycin D. Minimal Medium + Streptomycin E. Methionine, threonine, leucine, and thiamine + Streptomycin 7. ( ) From an F+ strain with markers edebin that circular order), which of the following derived Hir's is impossible? A centers first and elast B. Centers first and d last C. d enters first and c last D. d enters first and e last E e enters first and blast 8. (pr). A bacterial cell contains a single copy of a transposon in which one strand carries G at one site (the wild-type base at this site) and the other strand carries a T (which confers a mutant phenotype). If this cell is allowed to divide through several divisions, but the transposon transposes at the first division through replicative transposition, then the colonies derived from these cells will be: A. Mosaic, with wild-type and mutant sectors B. All mutant C. All wild-type D. All GT heteroduplexes E. Some wild-type and some mutant

Answer 1

6) Option D- Minimal medium + Streptomycin

7) Option A- c enters first and e last

8) Option A- Mosaic , with wild- type and mutant type